The effect of complexing agent on the crystallization of ZnO nanoparticles

Abstract

In this work, some structural and optical properties of the zinc oxide (ZnO) nanoparticles were studied. The highly crystalline ZnO nanoparticles were produced by the hydrothermal and solgel methods. The analyses of the XRD patterns, STEM images and UV spectroscopy showed that the size of the nanoparticles prepared by oxalic acid was smaller than the ones by urea. The properties of oxalic acid and urea were also investigated to determine the most effective crystallization process of ZnO nanoparticles. It has been shown that pH, decomposition temperature and activity coefficient of the complexing agent have certain effects on crystallization process.

Effect of Annealing on Gas Sensing Performance of Nanostructured Zno Thick Film Resistors

“…Similar reports of increase in crystallinity with different annealing temperature can be seen in literature [12]. Interplanar and interchain distances were marginally changed because the angle of the peak (θ) did not vary significantly.…”

“…Inserting this into (8) where Ra is irrelevant to P H 2 S gives the response S = Ra/Rg ∝ P H 2 S (12) Similarly, when the dominating species that participating in the reaction is O − , we obtain…”

Zirconium–Carbon Hybrid Sorbent for Removal of Fluoride from Water: Oxalic Acid Mediated Zr(IV) Assembly and Adsorption Mechanism

“…We believe the intentional use of complexing (or chelating) ligands that can bind to particle surfaces or nuclei during the synthesis could be potentially useful to control the growth and final particle size distribution of the dispersed metal. Organic acids have demonstrated a positive effect on reduction of oxide nanoparticle size during the nucleation and aggregation stage. , This approach has not been systematically used to load Zr-containing nanoparticles onto carbonaceous surfaces such activated carbons and, thus, take advantage of the high mechanical strength, excellent permeability in flow-through systems, and high surface of activated carbon for future use in defluoridation processes for drinking water systems.…”

“…Organic acids have demonstrated a positive effect on reduction of oxide nanoparticle size during the nucleation and aggregation stage. 25,26 This approach has not been systematically used to load Zr-containing nanoparticles onto carbonaceous surfaces such activated carbons and, thus, take advantage of the high mechanical strength, excellent permeability in flow-through systems, and high surface of activated carbon for future use in defluoridation processes for drinking water systems. The aim of this research is to improve the fluoride adsorption capacity of granular activated carbon by controlling the particle size of Zr(IV)-containing particles with oxalic acid as complexing ligand during the impregnation process and to propose the possible fluoride adsorption mechanisms.…”